Regulations for connector technology are evolving. As signal speeds increase and the connector industry desires to move data faster over a Cat 5 or equivalent cable, there is a need for isolating magnetic devices capable of handling higher magnetizing forces and DC current bias. In a typical RJ45 type connector assembly where a modular plug mates in a male-female relationship with a modular jack, an isolating magnetic device is used in the female connector portion to handle direct current (“DC”) offsets. Such offsets may be caused by various factors including imbalances in the wires of the plug.
For example, data is frequently transmitted over a pair of conductive wires. When transmitting data, the pair of wires may ideally have voltage potentials to ground such that a voltage in one wire of the pair is equal and opposite to the voltage in the other wire of the pair. For example, one wire may have a potential of −2.5 volts and the other wire may have a potential of +2.5 volts. If there are imbalances in the pair of wires or extraneous electro-magnetic interference, the two wires may not have exactly equal and opposite voltages. For example, one wire may have −2 volts and the other wire may have +3 volts. Although there is still a net difference across the pair of wires of +5 volts (which may, for example, correspond to a logic “1”), such a voltage imbalance will generate a current imbalance. Conventional technology uses isolating magnetic devices and/or transformers to deal with such imbalances. However, prior art magnetic devices cannot physically handle the magnetizing force which may be induced by imbalanced DC current having high frequencies.
As an illustrative example, referring to FIG. 1, there is shown a transformer 40 in accordance with the prior art. Transformer 40 may be used as an isolating magnetic device. Transformer 40 is formed by winding wires 44, 46, 48 and 50 around a toroid shaped core 42. Core 42 has a substantially circular cross-section. Wires 44, 46, 48 and 50 are evenly wound around core 42 except in a gap area 38.
Such prior art solutions as discussed above can handle perhaps as much as 2 million bits per second. However, newer standards require that communications occur as high as one (1) or even ten (10) gigabits per second. The above prior art isolation magnetic device generally does not have the frequency response characteristic needed to inhibit the presence of DC current bias with communications of such speeds. Even those solutions capable of handling high speed (e.g. 2M bits per second) communications are not backward compatible (i.e. they cannot handle slower communications) and are frequently not in a conventional RJ45 type connector format. Such a format is common in the industry and most users have become comfortable with it.
Therefore, there is a need in the art for an isolation magnetic device which can handle high speed communications, is backward compatible, and which can conform to standard RJ45 type connector arrangements. There is also a need for a method for manufacturing such a device.